With increasing development of science and technology, electronic devices become more and more popular to personal users. The widely-used electronic devices include for example desktop computers, notebook computers, smart phones, tablet computers or the like. Each of these electronic devices has at least one circuit board. Moreover, at least one electronic component is fixed on the circuit board for executing a specified function. Moreover, through the cooperation of plural electronic components on the circuit board, the electronic device can be driven and operated. Generally, plural electrical contacts are formed on the circuit board so as to be electrically connected with these electronic components.
Generally, in the fabrication of the electronic device, a testing method should be performed to realize whether the functions of the electronic device are normal or not. The testing method which comprises a procedure of testing the circuit board before the electronic device is assembled and a procedure of testing the overall functions of the assembled electronic device after the electronic device is fabricated. By testing the circuit board, the manufacturer may realize whether any defects are present in the circuit board before the electronic device is assembled. If the procedure of testing the circuit board is not done and some defects are found after the electronic device is assembled, the manufacturer has to disassemble the electronic device to debug the circuit board. It is time-consuming to disassemble the electronic device to debug the circuit board.
Hereinafter, the structure of a testing device for testing a circuit board will be illustrated with reference to FIG. 1. FIG. 1 schematically illustrates the structure of a conventional testing device. As shown in FIG. 1, the conventional testing device 1 comprises a base body 11, a holder 12, a plastic plate 13 and plural testing probes 14. The holder 12 is disposed on the base body 11 for supporting an under-test circuit board 10. The plastic plate 13 is disposed on the base body 11, and located over the holder 12. The plural testing probes 14 are disposed on the plastic plate 13. Moreover, in response to the user's operation, the plastic plate 13 is movable relative to the base body 11 so as to be close to or far away from the holder 12. Moreover, the plural testing probes 14 are penetrated through the plastic plate 13, and the plural testing probes 14 are perpendicular to a bottom surface of the plastic plate 13. Consequently, as the plural testing probes 14 are moved toward the holder 12, the plural testing probes 14 are contacted with the circuit board 10 on the holder 12.
For testing the circuit board 10 which is placed on the holder 12, the plastic plate 13 is firstly moved downwardly by the user, and then the plural testing probes 14 are contacted with corresponding electrical contacts (not shown) of the circuit board 10. Then, after electricity is provided to the circuit board 10, the electrical properties (e.g. the resistance values, the capacitance values or the inductance values) of the plural electrical contacts of the circuit board 10 are measured. After the measured values of these electrical properties are obtained, the user may judge whether these electrical contacts are normal or abnormal by comparing the measured values of these electrical properties with preset electrical values. According to the comparing results, the user may determine whether the circuit board 10 passes the test or not. However, since the plural testing probes 14 are contacted with the corresponding electrical contacts during the process of testing the circuit board 10, the movement of negative ions may result in an electrostatic discharge effect. Due to the electrostatic discharge effect, the possibility of causing damage of the circuit board 10 increases.
Therefore, there is a need of providing a testing device for testing an under-test object while avoiding the generation of the electrostatic discharge effect.